u/Lord_of_the_Ringtone

If you need coverage there, you should buy the individual eSIM for Monaco, because it's not included in the regional European eSIM (for some reason).

And I didn't know that until I arrived in Monte Carlo.

But I used that regional sim in France, England, and Switzerland and it worked perfectly.

I want to bring a briefcase on the plane. It is almost small enough...

• Height = 4 to 5 cm above the limit (1.6 to 2 inches)
• Width = 2-3 cm above limit (0.8-1.2 in)
• Length = 4-5 cm above (1.6"-2")

Should I pay for a carry-on before the flight? (To avoid the larger fee at the gate)

Or they won't even notice or care?

I can't imagine they will measure it with a ruler and shout, "Two inches?! Too big!"